Abstract: Combination of mobile and fixed network observations is one development tendency of current seismic observation system. In order to solve the problems such as mutual independence between seismometers and seismic data acquisition instruments, inconvenient portability and high power consumption in mobile observation, this study develops a new low-power broadband sensor-integrated data logger, which contains a three-component seismometer, a data acquisition unit, a recording device and services. The instrument has a wide frequency bandwidth (60 s—80 Hz), high dynamic range (>140 dB) and low-power consumption (0.6 W), and is easy to carry. Whole weight of the instrument is about 15 kg, including the power supply system, GPS antenna and crates. This paper describes its apparant structure, hardware structure, low-power processing techniques, sensitivity correction, standard orientation and the orthogonal correction technique in detail. We have rigorously tested the main performance parameters of the instrument and given the specific test results. After the development of instrument was completed, we put it into mobile observation after the 2010 Yushu M_S7.1 earthquake. The test results show that this instrument can meet the requirements of mobile observation.